Obtaining anatomically correct ultrasound images with high temporal and spatial resolution is often challenging with conventional ultrasound imaging systems. The imaging of an organ that exhibits significant movement, such as the heart, poses a particularly difficult challenge. For example, with a conventional ultrasound imaging system, a two-dimensional image typically affords the best combination of temporal and spatial resolution. However, if the object being imaged exhibits significant out-of-plane motion, the result will be that the two-dimensional image is not anatomically correct. For example, while acquiring ultrasound data of a plane, as in a conventional two-dimensional acquisition, the plane is typically defined in a fixed position with respect to an ultrasound probe. Therefore, as the object being imaged moves, different portions of the anatomy may be captured at different times during the image acquisition. For example, if the structure being imaged exhibits significant motion in a generally vertical plane while the plane of the two-dimensional image is generally horizontal, then the two-dimensional image will includes slices from different heights of the object instead of being focused exclusively on the structure of interest.
One way around the aforementioned problem is to acquire volumetric, or three-dimensional ultrasound data of the object. If the volume of acquisition is large enough to include the structure of interest throughout its full range of motion, it is possible to view the structure of interest at multiple phases. However, one problem with acquiring three-dimensional ultrasound data is that it typically takes significantly more time to acquire three-dimensional ultrasound data compared to two-dimensional ultrasound data. As a result, either one or both of the temporal resolution and the spatial resolution typically suffers when viewing a real-time three-dimensional image. If the three-dimensional ultrasound data acquisition is gated over multiple cardiac cycles, it is possible to increase the spatial resolution and the temporal resolution, but then the user may lose the advantage of real-time feedback.
For at least the reasons discussed hereinabove, there is a need for an ultrasound imaging system and method for obtaining anatomically correct ultrasound data with acceptable temporal and spatial resolution.